feat(katana): starknet gas oracle placeholder (#2874)

Starknet doesn't yet provide a way to query the L2 gas prices from the current RPC specs (but soon will be in [RPC v0.80 ](https://github.com/starkware-libs/starknet-specs/blob/c94df2c5866e11c866abd3d234b0d5df681073c3/api/starknet_api_openrpc.json#L1603-L1607)), so this is merely a placeholder to make sure that we can run the node with Starknet as the settlement layer when specified in the `ChainSpec`. Reference: #2870

crates/katana/chain-spec/src/lib.rs

@@ -10,7 +10,6 @@ use katana_primitives::chain::ChainId;
 use katana_primitives::class::ClassHash;
 use katana_primitives::contract::ContractAddress;
 use katana_primitives::da::L1DataAvailabilityMode;
-use katana_primitives::eth::{self, Address as EthAddress};
 use katana_primitives::genesis::allocation::{DevAllocationsGenerator, GenesisAllocation};
 use katana_primitives::genesis::constant::{
     get_fee_token_balance_base_storage_address, DEFAULT_ACCOUNT_CLASS_PUBKEY_STORAGE_SLOT,
@@ -24,7 +23,7 @@ use katana_primitives::genesis::Genesis;
 use katana_primitives::state::StateUpdatesWithClasses;
 use katana_primitives::utils::split_u256;
 use katana_primitives::version::{ProtocolVersion, CURRENT_STARKNET_VERSION};
-use katana_primitives::Felt;
+use katana_primitives::{eth, Felt};
 use lazy_static::lazy_static;
 use serde::{Deserialize, Serialize};
 use starknet::core::utils::cairo_short_string_to_felt;
@@ -63,7 +62,7 @@ pub struct FeeContracts {
 }
 
 #[derive(Debug, Clone, Serialize, Deserialize)]
-#[serde(rename_all = "camelCase")]
+#[serde(tag = "type", rename_all = "camelCase")]
 pub enum SettlementLayer {
     Ethereum {
         // The id of the settlement chain.
@@ -72,11 +71,11 @@ pub enum SettlementLayer {
         // url for ethereum rpc provider
         rpc_url: Url,
 
-        account: EthAddress,
+        /// account on the ethereum network
+        account: eth::Address,
 
         // - The core appchain contract used to settlement
-        // - This is deployed on the L1
-        core_contract: EthAddress,
+        core_contract: eth::Address,
     },
 
     Starknet {
@@ -86,11 +85,10 @@ pub enum SettlementLayer {
         // url for starknet rpc provider
         rpc_url: Url,
 
-        // the account address that was used to initialized the l1 deployments
+        /// account on the starknet network
         account: ContractAddress,
 
         // - The core appchain contract used to settlement
-        // - This is deployed on the L1
         core_contract: ContractAddress,
     },
 }

crates/katana/core/src/backend/gas_oracle.rs

@@ -16,24 +16,22 @@ const BUFFER_SIZE: usize = 60;
 const INTERVAL: Duration = Duration::from_secs(60);
 const ONE_GWEI: u128 = 1_000_000_000;
 
-// TODO: implement a proper gas oracle function - sample the l1 gas and data gas prices
-// currently this just return the hardcoded value set from the cli or if not set, the default value.
 #[derive(Debug)]
-pub enum L1GasOracle {
-    Fixed(FixedL1GasOracle),
-    Sampled(SampledL1GasOracle),
+pub enum GasOracle {
+    Fixed(FixedGasOracle),
+    Sampled(EthereumSampledGasOracle),
 }
 
 #[derive(Debug)]
-pub struct FixedL1GasOracle {
+pub struct FixedGasOracle {
     gas_prices: GasPrices,
     data_gas_prices: GasPrices,
 }
 
 #[derive(Debug, Clone)]
-pub struct SampledL1GasOracle {
+pub struct EthereumSampledGasOracle {
     prices: Arc<Mutex<SampledPrices>>,
-    l1_provider: Url,
+    provider: Url,
 }
 
 #[derive(Debug, Default)]
@@ -50,29 +48,39 @@ pub struct GasOracleWorker {
     pub data_gas_price_buffer: GasPriceBuffer,
 }
 
-impl L1GasOracle {
+impl GasOracle {
     pub fn fixed(gas_prices: GasPrices, data_gas_prices: GasPrices) -> Self {
-        L1GasOracle::Fixed(FixedL1GasOracle { gas_prices, data_gas_prices })
+        GasOracle::Fixed(FixedGasOracle { gas_prices, data_gas_prices })
     }
 
-    pub fn sampled(l1_provider: Url) -> Self {
+    /// Creates a new gas oracle that samples the gas prices from an Ethereum chain.
+    pub fn sampled_ethereum(eth_provider: Url) -> Self {
         let prices: Arc<Mutex<SampledPrices>> = Arc::new(Mutex::new(SampledPrices::default()));
-        L1GasOracle::Sampled(SampledL1GasOracle { prices, l1_provider })
+        GasOracle::Sampled(EthereumSampledGasOracle { prices, provider: eth_provider })
+    }
+
+    /// This is just placeholder for now, as Starknet doesn't provide a way to get the L2 gas
+    /// prices, we just return a fixed gas price values of 0. This is equivalent to calling
+    /// [`GasOracle::fixed`] with 0 values for both gas and data prices.
+    ///
+    /// The result of this is the same as running the node with fee disabled.
+    pub fn sampled_starknet() -> Self {
+        Self::fixed(GasPrices { eth: 0, strk: 0 }, GasPrices { eth: 0, strk: 0 })
     }
 
     /// Returns the current gas prices.
     pub fn current_gas_prices(&self) -> GasPrices {
         match self {
-            L1GasOracle::Fixed(fixed) => fixed.current_gas_prices(),
-            L1GasOracle::Sampled(sampled) => sampled.prices.lock().gas_prices.clone(),
+            GasOracle::Fixed(fixed) => fixed.current_gas_prices(),
+            GasOracle::Sampled(sampled) => sampled.prices.lock().gas_prices.clone(),
         }
     }
 
     /// Returns the current data gas prices.
     pub fn current_data_gas_prices(&self) -> GasPrices {
         match self {
-            L1GasOracle::Fixed(fixed) => fixed.current_data_gas_prices(),
-            L1GasOracle::Sampled(sampled) => sampled.prices.lock().data_gas_prices.clone(),
+            GasOracle::Fixed(fixed) => fixed.current_data_gas_prices(),
+            GasOracle::Sampled(sampled) => sampled.prices.lock().data_gas_prices.clone(),
         }
     }
 
@@ -81,7 +89,7 @@ impl L1GasOracle {
             Self::Fixed(..) => {}
             Self::Sampled(oracle) => {
                 let prices = oracle.prices.clone();
-                let l1_provider = oracle.l1_provider.clone();
+                let l1_provider = oracle.provider.clone();
 
                 task_spawner.build_task().critical().name("L1 Gas Oracle Worker").spawn(
                     async move {
@@ -97,7 +105,7 @@ impl L1GasOracle {
     }
 }
 
-impl SampledL1GasOracle {
+impl EthereumSampledGasOracle {
     pub fn current_data_gas_prices(&self) -> GasPrices {
         self.prices.lock().data_gas_prices.clone()
     }
@@ -107,7 +115,7 @@ impl SampledL1GasOracle {
     }
 }
 
-impl FixedL1GasOracle {
+impl FixedGasOracle {
     pub fn current_data_gas_prices(&self) -> GasPrices {
         self.data_gas_prices.clone()
     }
@@ -289,10 +297,10 @@ mod tests {
     #[ignore = "Requires external assumption"]
     async fn test_gas_oracle() {
         let url = Url::parse("https://eth.merkle.io/").expect("Invalid URL");
-        let oracle = L1GasOracle::sampled(url.clone());
+        let oracle = GasOracle::sampled_ethereum(url.clone());
 
         let shared_prices = match &oracle {
-            L1GasOracle::Sampled(sampled) => sampled.prices.clone(),
+            GasOracle::Sampled(sampled) => sampled.prices.clone(),
             _ => panic!("Expected sampled oracle"),
         };
 

crates/katana/core/src/backend/mod.rs

@@ -1,6 +1,6 @@
 use std::sync::Arc;
 
-use gas_oracle::L1GasOracle;
+use gas_oracle::GasOracle;
 use katana_chain_spec::ChainSpec;
 use katana_executor::{ExecutionOutput, ExecutionResult, ExecutorFactory};
 use katana_primitives::block::{
@@ -41,7 +41,7 @@ pub struct Backend<EF: ExecutorFactory> {
 
     pub executor_factory: Arc<EF>,
 
-    pub gas_oracle: L1GasOracle,
+    pub gas_oracle: GasOracle,
 }
 
 impl<EF: ExecutorFactory> Backend<EF> {

crates/katana/node/src/lib.rs

@@ -18,7 +18,7 @@ use dojo_metrics::{Report, Server as MetricsServer};
 use hyper::Method;
 use jsonrpsee::RpcModule;
 use katana_chain_spec::SettlementLayer;
-use katana_core::backend::gas_oracle::L1GasOracle;
+use katana_core::backend::gas_oracle::GasOracle;
 use katana_core::backend::storage::Blockchain;
 use katana_core::backend::Backend;
 use katana_core::env::BlockContextGenerator;
@@ -202,20 +202,17 @@ pub async fn build(mut config: Config) -> Result<Node> {
     // Check if the user specify a fixed gas price in the dev config.
     let gas_oracle = if let Some(fixed_prices) = &config.dev.fixed_gas_prices {
         // Use fixed gas prices if provided in the configuration
-        L1GasOracle::fixed(fixed_prices.gas_price.clone(), fixed_prices.data_gas_price.clone())
+        GasOracle::fixed(fixed_prices.gas_price.clone(), fixed_prices.data_gas_price.clone())
     } else if let Some(settlement) = &config.chain.settlement {
         match settlement {
+            SettlementLayer::Starknet { .. } => GasOracle::sampled_starknet(),
             SettlementLayer::Ethereum { rpc_url, .. } => {
-                // Default to a sampled gas oracle using the given provider
-                L1GasOracle::sampled(rpc_url.clone())
-            }
-            SettlementLayer::Starknet { .. } => {
-                todo!("starknet gas oracle")
+                GasOracle::sampled_ethereum(rpc_url.clone())
             }
         }
     } else {
         // Use default fixed gas prices if no url and if no fixed prices are provided
-        L1GasOracle::fixed(
+        GasOracle::fixed(
             GasPrices { eth: DEFAULT_ETH_L1_GAS_PRICE, strk: DEFAULT_STRK_L1_GAS_PRICE },
             GasPrices { eth: DEFAULT_ETH_L1_DATA_GAS_PRICE, strk: DEFAULT_STRK_L1_DATA_GAS_PRICE },
         )